Older adults find it difficult to meet moderate and vigorous exercise targets. Given that a dose-response exists for physical activity and health benefits, Phillip B Sparling and colleagues argue that a change in message to reduce sedentary time and increase light activities may prove more realistic and pave the way to more intense exercise

Over the past decade, research has increased our understanding of the effects of physical activity at opposite ends of the spectrum. Sedentary behaviour—too much sitting—has been shown to increase risk of chronic disease, particularly diabetes and cardiovascular disease.12 There is now a clear need to reduce prolonged sitting. Secondly, evidence on the potential of high intensity interval training in managing the same chronic diseases, as well as reducing indices of cardiometabolic risk in healthy adults, has emerged.34 This vigorous training typically comprises multiple 3-4 minute bouts of high intensity exercise interspersed with several minutes of low intensity recovery, three times a week.

Between these two extremes of the activity spectrum is the mainstream public health recommendation for aerobic exercise, which is similar in many developed countries.56789 The suggested target for older adults (≥65) is the same as for other adults (18-64): 150 minutes a week of moderate intensity activity in bouts of 10 minutes or more. It is often expressed as 30 minutes of brisk walking or equivalent activity five days a week, although 75 minutes of vigorous intensity activity spread across the week, or a combination of moderate and vigorous activity are sometimes suggested. Physical activity to improve strength should also be done at least two days a week. The 150 minute target is widely disseminated to health professionals and the public. However, many people, especially in older age groups, find it hard to achieve this …